Have you seen this? A guy bought two McDonald's burgers in 1989, ate one, put the other in his pocket for some reason (?) and forgot about it until he took that jacket out again a year later. Thanks to all the preservatives and artificial goodness, the burger had barely changed.
So then he started buying burgers every year, dating them with the year, and starting a little burger museum in his basement. Now the burgers didn't stay pristine, they got pretty gross, but they didn't mold up like a real burger you made in your kitchen would. It's really fascinating, in a nasty-ass way.